Heavy Metal Distribution in Street Dust of Urban and Industrial Areas in Jeddah, Saudi Arabia

Abstract

The concentrations of heavy metals namely: Pb, Ni, Cd, Cr, Cu, Zn, Fe and Mn were measured in street dust samples. The samples were collected from the urban (Aljamaa district, main streets and substreets) and industrial areas of Jeddah city, Saudi Arabia. The concentrations of the measured metals were significantly higher in the main streets of the urban area than those found in the industrial area and substrates of the urban area. However, Pb was found in the highest levels in industrial area. The concentrations of the individual metals in street dust collected from the main streets and substreets of the urban area and industrial area averaged 70.36, 53.51 and 105.76 µg/g for Pb; 39.71, 24.00 and 27.28 µg/g for Ni; 2.24, 1.32 and 1.57 µg/g for Cd; 72.93, 40.10 and 47.67 µg/g for Cr; 125.52, 83.32 and 93.66 µg/g for Cu; 340.85, 214.10 and 240.50 µg/g for Zn; 10199.42, 7678.84 and 7918.42 µg/g for Fe and 514.15, 389.69 and 400.64 µg/g for Mn, respectively. The ratios of main streets/substreets metal concentration in the urban area were 1.31, 1.65, 1.70, 1.82, 1.51, 1.59, 1.33 and 1.32 for Pb, Ni, Cd, Cr, Cu, Zn, Fe and Mn, respectively. The mean concentrations of measured heavy metals in street dust from both study areas were lower / higher or similar to those detected in other cities of the world. The average concentrations of Cu and Zn in street dust of the main street dusts of the urban area exceeded the permissible limit value of soil. Significant positive correlation coefficients were found between the concentrations of Cr, Cd, Cu and Zn and also between the concentrations of Fe, Mn and Ni, Cr, Cu and Zn in the street dust of the urban area. On the other hand, insignificant positive correlation coefficients were found between the concentrations of Pb and other metals in street dust of the urban area. In the industrial area, significant positive correlation coefficients were found between the concentrations of heavy metals in the street dust.